Air balanced pumping unit and pressure regulation thereof



1 E. w. PATTERSON 2,293,916

AIR BALANCED PUMPING UNIT AND :PRES SURE REGULATION THEREOF Filed Aug.3, 1940 fl'QaJ'W-PQZZEI'SOIL INVENTOR ATTORNEY Patented Aug. 25, 1942"warren STATES 'PATE AIR. BALANCED PUIWPING UNIT AND PRES- SUREREGULATION THEREOF Edgar W. Patterson, Long- Beach, Calif., assignor ofone-half to Charles M. OLeary, Jr., Los An- I geles, Calif.

Application August 3, 1940, Serial No. 350,282

8 Claims. (01. 230-30) The present invention relates generally to airbalanced pumping units, and is especially conc'erned with the pressureregulation thereof, its

primary object being the provision of a system of regulation by which tosteadily maintain a predetermined set pressure in the air reservoirthrough the employment of means unaffected'in the desired operationthereof by the fluctuations of pressure in said reservoir necessarilyincident to normal operation of the unit.

More particularly, the invention has to do with the type of air balancedpumping unit such as disclosed in my Patent Number 2,148,638, grantedFebruary 28, 1939, wherein air is supplied, by a reciprocatingcompressor actuated by the walking beam of the unit, to a reservoir forpressure which is in open communication with the working chamber of abalance cylinder so arranged that it opposes downward rocking movementof the walking beam and, in such movement, stores up energy whichassists in the upward rocking movement of the beam. Since the reservoir,as above stated, is necessarily in open communication with the workingchamber of the balance cylinder, it follows that it is subject toalternate rise and fall of pressure therein as the walking beamrespectively lowers and rises.

It is the purpose of the present invention to 1 provide simple,effective means for maintaining in-the reservoir a predetermined anddesired low pressure, the operation and function of which means will notbe affected in any manner by the rise and fall of pressure in thereservoir during normal operation, and which means readily responds tomanual regulation for setting the desired pressure and automaticpressure control in its subsequent functioning.

A further object of theinvention is the provision of an efflcientpressure regulating system for the above purposes, which will besubstantially fool-proof in its adjustments for diiferent pressures, andin which, for this purpose, no valves need be adjusted and the setpressure is always plainly visible.

A still further object of the invention is the provision of a pressureregulating system in which, in spite of .the fluctuating reservoirpressure, its lowest point will be determined and controlled at alltimes by means which remain stationary except when pressure is to besupplied to the reservoir, so that for long periods its parts not besubject to wear nor disarrangement through the influence of suchfluctuations.

With the above general objects in mind, other and further objects of theinvention, as well as.

its operating and functional advantages, will clearly appear in thecourse of the following description detailing one way of carrying theinvention into practical effect.

' Carefully bearing the foregoing'in mind, the

invention will be better understood and more thoroughly appreciated fromthe following description and by reference to the accompanying drawing,forming a part of this specification, and wherein,

Figure 1 is a side elevational view, partly broken away to better showcertain parts, of an air balanced pumping unit embodying the presentinvention.

Figure 2 is a vertical sectional view through the compressor, showingits adjustable beam conon line 5-5 of Figure 2, and showing a slightmodification.

Figure 6 is an' enlarged view showing the regulator in-central verticalsection.

Figure 7 is a top plan view of the pressur regulator. I i o Figure 8 isa side elevation of the regulator of Figure 6. v

Figure 9 is a detail side view of the inner adjusting sleeve of theregulator.

Figure 10 is a detail transverse sectional view taken substantially online I0l0 of Figure 9, and,

Figure 11 is a detail sectional and view of the valve of Figure 6.

Referring nowto these figures, and particularly to Figure 1, the presentinvention has been enlarged "illustrated in connection with an airbalanced said working chamber and the air reservoir 20.

The beam lliis shown as actuated in its up and down swinging movementson a bearing atop the Samson post 22, by pitmans 23, from crank discs 4side of pitman 23 with respect .to the balance cylinder l5.

The working chamber 3| of the compressor is, as best seen in Figure 2,below its piston 21, and

take pipe 32 and an outlet pipe 33, the former being open to atmosphereand provided with a check valve 34 opening toward the compressor, andthe latter extending to the reservoir 20, as clearly seen by acomparison of Figures 1 and 3, and having therein two spaced apart checkvalves 35 and 36, both opening in a direction away from thecompressoran'd toward the reservoir, for a purpose which will presentlyappear.

The compressor outlet pipe 33, which is the reservoir feed pipe, is alsopreferably provided with a pressure indicator 31 whose dial will alwaysrespond to, and plainly show, the pressure in the reservoir as it risesand falls with the low-- ering and rising movements of the beam l6 andbalance cylinder IS, the lowest pressure being when the balance cylinderand the beam are at the top of their stroke. It is for this reason thatthe pressure indicator 31 is placed between the reservoir and the secondcheck valve 36.

As best seen in Figure 6, the check valve 34 of the compressor intakepipe, is of a type employing a valve member 38, also seen' in Figure-11. This valve member 38 may be depressed, against the tension of itscontrolling spring, to hold the same away from its seat and in thismanner render the valve inactive so that the compressor will take in anddischarge air through its intake line, and no air will be fed throughthe reservoir feed pipe 33. To-control valve 34 in the above manner theinvention provides the following.

Mounted on the check valve 34 is a regulator,-

generally indicated at 33,. which functions without regard to thefluctuations of pressure in the reservoir, and has a verticallycylindrical casing 40 in which a vertically shiftable sleeve 41 isslidably mounted. Through the casing and through the otherwise closedlower end of the .with this chamber there communicates an inits lowerend will engage and depress the valve member 38 to a position renderingcheck valve 34 inoperative as such, and permitting air to be bothtaken'in and discharged through the intake pipe 32.

The effective tension of spring 43 may be trolling spring 43.

sleeve 4|, is a vertically, longitudinally shiftable control stem 42,whose lower end extends through the lower end of casing 40 into thecheck valve 34 to a point in vertical alignment with the valve member38.

The upper end of the stem 42 movably projects upwardly through theotherwise closed upper end of the casing 40, and around said stem,within casing 40, is a controlling spring 43 compressed between an uppercross pin 44 of stem 42 and the lower closed end of the sleeve 4|. Thisspring 43 thus normally presses the stem 42 upwardly to a point whereits lower end is above the valve member 38 so as to allow the valve 34In order that the setting of the spring tension may be quicklyand'accurately known at all times, the sleeve 4|, as best seen inFigures 8 and '9, may have thereon vertically aligned gradua tions 50,in pounds pressure, in line with a sight opening 5| through the wall ofthe casing 40.

As best seen in Figures 1, 3 and 6, a pressure communicating tube 52opens at one end into the cap 45 of the regulator 33, the other end ofsaid tube opening through the top of, and into, a surge or bufler tank53 whose lower end is in open communication with the reservoir feed pipe33 at a point between the two check valves 35 and 36. It is thus thepressure in this tank 33 which forces the controlling stem 42 downwardlythrough the regulator.

The capacity of the surge or buffer tank 53 is such as to absorb intoits relatively quiescent interior each surge of pressure through thereservoir feed pipe 33 in the operation of the compressor. It is,moreover, protected from the fluctuations of' pressure in the reservoirby the check valve 36, andits pressure cannot, of course. return to thecompressor by reason of the check valve 35.

It is apparent from the foregoing that during pumping of pressure intothe reservoir, the compressor 25 draws air through check valve 34, with,

the controlling stem 42 of the regulator held in its upper positionbythe spring 43 adjusted, for example to flfty -pounds. During the fillingof the reservoir with the balance cylinder in action, there is aconstant rise and fall of reservoir pressure, which corresponds with thestrokes of the compressor, but no rise of reservoir pressure above thatof a single delivery stroke of the compressor can afl'ect the pressurein the surge or bufl'er tank 53 and, as above stated, the capacity ofthe latter is such that no sudden rise of its pressure can result from asingle stroke of the compressor. In this way the rise of pressure in thesurge tank is gradual in the same manner as the rise of the lowestpressure in the reservoir, or in other words that pressure fed theretoby the compressor. when the point is reached where pressure in the surgetank equals fifty pounds, the controlling stem 42 will be forced downand the pumping action of the compressor will cease by reason of theinoperative condition of its intake valve 34. From this point on, duringoperation of th pumping unit, the several parts of the regulating systemare stationary until such time as the pressure in the reservoir fallsbelow that within the surge tank 53, permitting pressure to flow fromthe latter into the reservoir past the check valve 36, whereupon thespring of the regulator then lifts the stem thereof against the reducedpressure within the surge tank and restores the intake valve 35 of thecompressor to operative condition It is plain, as seen in Figure 5, thatinstead of utilizing the regulator 39 on the check valve '34 of thecompressor intake pipe 32, it may be employed on a separate pipe 54 toatmosphere. The result is the same, the working chamber of thecompressor being in each instance vented to atmosphere so that itmerelytakes in and exhausts airwithout compressing, during all the period ofoperation of the unit except when pressure must be replenished from timeto time in the reservoir.

Having thus fully described the invention, what is claimed is:

1. In a pressure control and supply system, a

reservoir and at the same time adapt the tank vto bleed pressure intothe reservoir when pressure in the latter falls below tank pressure, anda pressure connection between the tank and the said regulator forcontrolling the latter.

4. In a pressure control and supply system, a

pressure reservoir subject in operation to constant fluctuations betweenhigh and low pressures, a constantly operating compressor for feedingpressure into said reservoir whenever low pressure therein falls below apredetermined point, a feed line between the compressor and reservoir, amanually regulated and pressure controlled means for loading andunloading the compressor, a surge or bufier tank connected to the feedline and of a size rendering the same subpressure reservoir subject inoperation to constant fluctuations between high and low pressures, aconstantly operating compressor for supplying pressure into saidreservoir whenever low pressure therein falls below a predeterminedpoint, a feed line from the compressor to the reservoir, a pressurecontrolled regulator having means for loading and unloading thecompressor, a bufier tank connected to receive pressure supplied to thereservoir whenthe compressor is loaded, and of a capacity to'insuregradual rise of pressure therein, a connection between the tank and thereservoir having therein a check valve opening toward the reservoirwhereby to protect the tank from high pressures in the reservoir due topressure fluctuations, while at the same time adapt the tank to bleedpressure into the reservoir when pressure in the latter falls below tankpressure, and a pressure connection between said bufier tank and theregulator for controlling the latter.

ject to gradual rise of pressure therein when the compressor is loaded,a check valve in the feed line between the compressor and bufier tankand a opening toward the latter to prevent bleeding of tank pressureinto the compressor when the lat- 2. In a pressure control and supplysystem, a

said tank having a valved pressure connection.

with the reservoir limiting flow of pressure in a direction from thetank to the reservoir, and a pressure connection between said tank andthe ,said regulator for controlling the latter.

3. In a pressure control and supply system, a

pressure reservoir subject in operation to con-' stant fluctuationsbetween high and low pressures, a constantly operating compressor forsupplying pressure into said reservoir whenever low pressure thereinfalls below a predetermined point, a feed line from the compressor tothe reservoir, a pressure controlled regulator having means for loadingand unloading the compressor, a buffer tank connected to the feed lineand of a capacity subjecting'the same to gradual rlse in pressure duringseveral successive strokes of the loaded compressor, a check valvebetween the said tank and the compressor, preventingbleed= ing of tankpressure into the compressor, a second check valve between the tank andreservoir, opening toward the latter whereby to protect the tank againstfluctuating high pressures in the ter is unloaded, a second check valvebetween the buffer tank and the reservoir opening toward the latterwhereby the tank is protected against pressure fluctuations in thereservoir, and at the same time adapted to bleed its pressure into thereservoir when pressure in the latter falls below the predetermined lowpressure, whereby the 'low pressure in the tank and reservoir will bethe same at all times, and a pressure connection between said tank andthe compressor loading and unloading means for controlling the latter.

5. In a pressure regulating system, a pressure controlled, manuallyadjustable regulator for the loading and unloading of a compressor, saidregulator consisting of a casing having a slotted wall and provided alsowith a sight opening, a sleeve sliclably interfltting said casing havinga member outstanding through the slotted wall, and also having alengthwise series of graduations in pounds pressure, arranged toindividually show through the sight opening, a member adjustable on theexterior surface of the casing and engaging said sleeve member to adjustthe sleeve lengthwise of, and within, the casing, an axially shiftableoperating rod within, and projecting beyond one end of, the casing, aspring connected at one end to the rod and. anchored at its other end onthe'sleeve for urging the rod in one direction, a closed cap on theother end of the casing around the other end of the rod, 2. bellowswithin said cap engaging the latter end of the rod, and a pressureconnection for supplying pressure against'the bellows for shifting therod in the opposite direction.

6. In a pressure regulating system, a pressure controlled, manuallyadjustable regulator for the loading and unloading of a compressor, saidregulator consisting of a casing having a slotted wall and provided alsowith a sight opening a sleeve slidably interfitting said casing, havinga member outstanding through the slotted casing wall, and also having alengthwise series of graduations in pounds pressure, arranged toindividually show through the sight opening, a member adjustable on theexterior surface of the casing and engaging said sleeve member to adjustthe sleeve lengthwise of, and within, the casing,

an axially shiftable operating rod within, and projecting beyond one endof, the casing, a spring connected at one end to the rod and anchored atits other end on the sleeve for urging the rod in one direction, andpressure actuated means for urging the rod in the opposite direction.

7. In a pressure regulating system, a pressure controlled and manuallyadjustable regulator including a lengthwise slotted casing having asight opening in its wall, an axially shiitable operating rod in thecasing and projecting at one end through the respective end 01' thecasing, pressure actuated means cooperating with the other in resistingpressure acfiuated movements of the rod, the said spring abutment memberincluding a part elongated lengthwise 01, and within, the casing havingthereon graduations in pounds pressure arranged to individually. showthrough the said sight opening of the casing.

8. In a pressure regulating system, a pressure controlled and manuallyadjustable regulatorincluding a casing having a sight opening in itswall, an operating rod shiitable axially in the casing and projectingtherefrom at one end, pressure actuated means cooperating with the otherend of said rod for shitting the latter in one direction, a spring inthe casing and in connection at one end with the rod for urging thelatter in the opposite direction, a member shittable lengthwise withinthe casing and forming an adjustable abutment tor the other end oi thespring and having a part thereof elongated lengthwise oi the casing,provided with graduations in pounds pressure arranged thereon to in-'dividually show through the sight opening of the casing, and a membermanually adjustable on the exterior of the casing and operativelyconnected with said spring abutment for shifting the latter to vary theeil'ective tension 0! the spring independent of pressure actuation oi.the rod.

EDGAR W. PATTERSON.

